This invention relates generally to door lock hardware and more particularly to a method and design for automatic assembly of mortise lock bolts.
Bolts for mortise locks are frequently made from hardened components in order to impart durability to the locksets. This fact not only increases the cost of such locks, but also makes fabrication of the parts and assembly of the locks more difficult. As an example, assembly of the bolt for a mortise lock is difficult and may result in excessive scrap losses.
Most commonly, mortise lock bolts are made by inserting the draw bar into a bore in the bolt body and drilling a transverse hole through the bolt body and the draw bar. Since the bolt body is usually through hardened while the draw bar is case hardened, there is an increased probability of the drill wandering at the interface between the two components. This can cause breakage of drill bits, which is costly and time consuming to deal with; or crooked holes, which make assembly difficult if not impossible. If drilled separately, there is a possibility that holes in the bolts won't match holes in the draw bars when the draw bars are inserted in the bolt bodies, and assembly will still be impossible or difficult, since pins will not press into holes which are not in alignment. Moreover, even if the holes are perfectly directed on the diameters of the bolt body and the draw bar, any slight misalignment of insertion of the bar into the bore will again make it impossible to press the spring pin into the drilled hole.
The foregoing illustrates limitations known to exist in present bolt assemblies for mortise locks and their method of assembly. It would, therefore, be advantageous to provide an alternative directed to overcoming one or more of those limitations. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.